What a difference a day makes. Six months ago Adam Gemili was playing right-back for Thurrock FC in the Blue Square South division. Now he is the fastest 100m sprinter in the country and a contender for Great Britain's Olympic team. It all happened on Saturday, when the 18-year-old was competing in Regensburg, Germany. Gemili, whose personal best was 10.23sec, ran 10.11 in the heats and then 10.08 in the final. That time puts him second in the European rankings for 2012, behind France's world 200m bronze medallist Christophe Lemaitre.

"When I crossed the line in 10.08 it was the most amazing feeling in the world," Gemili said on Sunday. "When I ran my heat and saw I'd run 10.11 I jumped into the air while I was still slowing down. The physios told me to calm it down else I'd end up injuring myself. So I was a bit calmer after the .08 but it was still the best feeling ever."

Gemili started sprinting only in 2010, when his school entered him in a local athletics competition. He had such natural talent that he won silver in the 100m at the European junior championships the next year. Until then he had been focused on his career as a footballer. He was on the books at Chelsea but now finds himself playing as a semi-pro with Dagenham & Redbridge. They sent him on loan to Thurrock, who finished bottom of the Blue Square South. "I hope this year could be a turning point in helping me decide which sport to focus on," he told Athletics Weekly. "But it does depend on what I run."

"This year is more of a split, I'm a lot more focused on athletics," Gemili said at the start of 2012. "Up until Christmas I was doing more football but since then athletics has taken more of a priority in trying to make it to the world juniors."

His priorities, you guess, have been hastily revised. Only one Briton has run faster as a junior and that was Dwain Chambers. The two are now likely to be rivals at the Olympic Games trials on 22‑23 June. Gemili's time would have put him in every Olympic final with the exception of Beijing 2008, when it would have left him in 11th place overall. Whether he can replicate his run under pressure is another question.

Gemili has been training under the coach Michael Afilaka, alongside the Olympic 100m finalist Jeanette Kwakye. "I've learned so much from him and the whole group are brilliant," Gemili said. "Jeanette is brilliant as a training partner but also as a role model, having been to an Olympic final and having a world [indoor] medal. It's just been such an eye opener." He and Afilaka have been working on his technique, which he describes as "not the best".

Until now it has been something of an embarrassment to British athletics that so much attention is lavished on Chambers, who is coming to the end of his career. Jason Gardener, the 2004 world indoor 60m champion, had said of Chambers' younger rivals: "The truth is, and I think our athletes will agree, if they are being honest with themselves, is that they are just not good enough." As of now, though, there is a new kid in the blocks. With the Olympic trials only three weeks away, his timing could not be better.